Snarky metacomment: The section entitled How were drawstrings deemed to be a "substantial product hazard"? concerns itself entirely with the bureaucratic mechanism of declaring them a hazard, not the plain English interpretation "Why are these a problem?" Fortunately, there is an earlier section that does address that question.

Apparently, in Washington, it is not sufficient to dot your i's and cross your t's, but you must be seen doing so in accord with the prescribed process for i-dotting and t-crossing as laid out in ASTM F 1816-97 16 CFR § 1120.3(b)(1).